This invention relates to a feeding and opening device for an open-end spinning arrangement, having a feeding roller and a movable feeding table which has a feeding surface which forms a clamping point together with the feeding roller, and having a tuft support which follows the feeding table and has a supporting surface for a tuft which is situated opposite a mounting of an opening roller.
In the case of the feeding and opening devices used currently in practice in open-end spinning machines, the tuft support is as a rule constructed in one piece with the feeding table. The movable feeding table is pressed against the feeding roller by means of spring force, in which case it carries out movements in the radial direction to the feeding roller as a result of fluctuations in the thickness. Because of these movements, the supporting surface also shifts relative to the mounting of the opening roller.
It is also known (European Patent Document EP-A 0 291 711) to construct the feeding table and the tuft support in one piece with a housing surrounding the opening roller. In this case, it is provided that either the housing is radially movable with respect to the feeding roller or the feeding roller is movable in the circumferential direction with respect to the opening roller. Also in this case, the conditions change in the area in which the sliver with its tuft arrives in the mounting of the opening roller.
It is also known (German Patent Document DE-A 24 60 043) to provide the feeding table only with a supporting surface that is very short in the circumferential direction of the opening roller and to construct the remaining part of the supporting surface as a component of a housing surrounding the opening roller. Also in this case, the movements of the feeding table have the result that the conditions change under which the tuft is offered to the mounting of the opening roller.
It is an object of the invention to provide a feeding and opening device of the initially mentioned type in which the sliver is fed to the opening roller in a manner that always remains the same to the maximum possible extent, and the tuft is offered to the opening roller in a manner that also always remains the same to the maximum possible extent.
This object is achieved in that the tuft support is arranged stationarily and has a guiding surface which is situated opposite the feeding roller, extends approximately radially with respect to the opening roller and continues the clamping surface of the feeding table.
In the case of this construction, it is not the movable feeding table which determines the point at which the sliver arrives at the mounting of the opening roller and how the tuft is offered to the mounting. Rather, these conditions are determined by the stationary tuft support so that these conditions will also not change when the feeding table moves in order to compensate for the differences in the thickness of the sliver.
In a further development of the invention, it is provided that the tuft support is arranged to be adjustable relative to the opening roller. By means of this adjustability, the combing-out conditions may be optimized and may be kept constant during the subsequent complete spinning operation.
In a further development of the invention, it is provided that the guiding surface of the tuft support facing the feeding roller is a partial-cylinder surface which is aligned approximately coaxially with respect to the feeding roller. As a result, it is achieved that a certain clamping of the sliver is still present in the area of the guiding surface of the tuft support.
In a further development of the invention, it is provided that the supporting surface of the tuft support is provided with edge borders. By means of this measure, it is achieved that the tuft cannot escape laterally during the combing-out which could impair the combing-out.
In a further development of the invention, it is provided that the tuft support is provided with a projection projecting into the are between the feeding roller and the opening roller which has a window for the guiding-through of a sliver. As a result, the occurrence of uncontrollable air flows in the area in which the sliver is guided to the opening roller can be largely prevented.
In a further development of the invention, it is provided that a sliding gap exists between the tuft support and the movable feeding table. Because of this sliding gap, it is prevented with sufficient reliability that fibers or the like, which may interfere with the spinning operation, can be caught there. In an embodiment of the invention, it is provided that the feeding table can be swivelled about a swivel shaft which is parallel to the feeding roller, and that the surfaces of the feeding table and of the tuft support, which are situated opposite one another, extend at least approximately concentrically with respect to the swivel shaft.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.